Perhaps the theory exams are to check that the candidate has actually read the books, has done a few practice calculations, and maybe, just maybe, has a bit of an idea of what's what with, and in, the subject material ?
That some of the questions get into the bowels of pedantry is unfortunate but that is an unfortunate sideline of the game, I guess ..
You would think though
JT that they might have you study some thing pertinent to the subject in hand and useful in the candidates forthcoming life. For the chaps who came after my time they had to study pressurisation and 767 systems for a ATPL(H). Name me a helicopter with pressurisation.
Might as well had the students do a quick course on brain surgery.